Giant halo at the neutron drip line

Relativistic Hartree-Bogoliubov theory in coordinate space is used to describe the chain of zirconium isotopes reaching from¹¹⁶Zr to the drip line nucleus ¹⁴⁰Zr. Pairing correlations are taken into account by a density dependent force of zero range. For neutron numbers larger than the magic number N=82 a giant neutron halo outside the core of ¹²²Zr is predicted. It is formed by up to six neutrons.